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Petr Vavruch also presents a two-day workshop anywhere in the world for US$1000 plus the necessary moderate expenses

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To say lubrication is important is an understatement. The role of lubrication in reducing friction, cooling, minimising wear, improving efficiency and avoiding unplanned downtime is as critical as the design or componentry of any machinery.
Aaron Stone

Graphene, a recently discovered material, is defined as a form of elemental carbon composed of a single flat sheet of carbon atoms arranged in a repeating hexagonal lattice. This lacy, honeycomb-like sheet of carbon atoms — essentially the most microscopic shaving of pencil lead you can imagine — is not just the thinnest material known in the world, but also incredibly light and flexible, hundreds of times stronger than steel, and more electrically conductive than copper.

The latest research interacts (a) molybdenum disulphide with nano-diamond particles on one surface and (b) a diamond-like carbon (DLC) surface on a ball to determine if superlubricity could be detected in a similar manner to graphene. It works by breaking moly and creating a onion-like carbon structure.

In machinery condition monitoring, a decision on the condition of a machine is dependent on the nature of its signals. For example, if the machine produces excessive noise and vibration, one gets a clue that something is not normal with the machine. These signals are usually time varying and need to be understood because they carry the information from the machine to the decision system, which can be a developed software or a person.
Machinery Condition Monitoring: Principles and Practices

In the lubrication industry it is pretty common to have heard of or experienced a lubrication issue due to mixing of incompatible lubricants. Issues encountered include excessive foaming, formation of precipitates or deposits and loss of key performance characteristics such as water separability. Given the gravity of the impact on machine reliability that these issues can cause, there is a demand for testing that can help predict if mixing two lubricants might result in operational issues. Although the lubricants may be deemed equivalent or comparable, that does not mean they are compatible.

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Are you having machine failures? Most companies are now realizing that maintaining clean oil is one of the best investments they can make, with contamination at the core of premature machinery failure and diminished lubricant life. A desiccant breather can be used as a first line of defence in preventing contaminants from ruining your equipment.

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Ninety percent of lubrication professionals say a lack of attention has negatively impacted the reliability of equipment at their plant.

Some antioxidants, such as butyl hydroxy toluene (BHT), will turn oil bright red when oxidizing during normal service. While not always cause for alarm, it is clear evidence that the antioxidant is depleting.

Viscosity is a fluid's characteristic demonstrating its resistance to flow. By definition, unit of dynamic ("absolute") viscosity is the poise, which is defined as the force in dynes required to move a surface one square centimetre in area past a parallel surface at a speed of one centimetre per second, with the surfaces separated by a fluid film one centimetre thick. We commonly use the centipoise (cP) and for kinematic viscosity the centistoke (cSt). There are other methods for determining viscosity, including Saybolt Universal Viscosity (SUV), Saybolt Furol viscosity, Engler viscosity, and Redwood viscosity. Since viscosity varies inversely with temperature, its value is meaningless until the temperature at which it is determined is reported. Viscosity can increase by oxidation and can be reduced by heating through thermal cracking.

Ford recommends using SAE 5W-50 viscosity grade for its GT-500 engine instead of the SAE 5W-20 or SAE 5W-30 used by other engines.
Arup Gangopadhyay

A small increase in lubricant viscosity may be due to the volatilization of base oil "lighter ends" after prolonged high-level operation (i.e. the lubricant has become "thicker"). Significant increases in viscosity up to 20 percent are regarded as severe, caused by incorrect addition of a higher viscosity lubricant, extensive soot contamination and base oil oxidation.

Applicable range of the above nomogram:This graph is designed for viscosity indexes between 0 and 100, viscosity of 2-20 cSt at 100 °C, and 6.4-495 cSt at 40 °C. I will publish the wider range graphs (up to VI=200 and viscosity of 2-50 cSt) in near future.
Instruction: This graph has 12 graded lines for viscosity and one for viscosity index. Six lines are nominated for viscosity at 100 and six for 40 centigrade that are paired with letters A, B, C, D, E, and F. To start with the graph:
1. Determine the kinematic viscosity (in cSt) at 100 °C on one of the curved graphs and highlight it with a dot.
2. Determine its paired line using the letters bellow the graph.
3. Find the viscosity at 40 °C on its pair and highlight it with the second dot.
4. Draw a straight line with two dots and using a ruler, and extend it to right hand side to intercept the "Viscosity Index" line.
5. The VI is the interception point of these two lines. You can report it with ±1 accuracy.
6. If you have limitation to measure viscosity at 40 and 100 °C, use ASTM D341 to estimate them.
M. Mahdi Karima

In 1929 Dean and Davis devised a system to express the viscosity/temperature relationship of an oil. The system, viscosity index (VI), was based on the viscosities of base oils obtained from a paraffinic Pennsylvanian crude oil, which was arbitrarily assigned a VI of 100, and base oils obtained from a naphthenic Gulf Coast crude oil, which was assigned a VI of 0.

Volatility of engine oil lubricants in service has become of increasing concern to equipment manufacturers because of oil consumption, engine deposits and air pollution effects. Two types of methods are used to assess volatility: The first is based on simulated distillation by gas chromatography (GCD), and the second, Noack volatility, measures bulk oil weight loss after heating at a prescribed temperature/time.

1.8 Foam, entrained air and air release, defoamant

The polar nature of engine oil additives gives rise to their foam-stabilizing properties. The splashing action or the mechanical agitation, or both, of the crankcase oil during engine operation causes air and other vapors to be whipped around, resulting in foam generation. In extreme cases, the oil actually can be lost because of the foam. The entrainment of the air in the oil can also decrease the ability of the oil to provide an effective hydrodynamic lubricating film because of the air bubbles that compromise the integrity of the film.

Defoamants are typically polydimethyl siloxanes of various molecular weights and are only required at a few parts-per-million concentration to control lubricant foaming. It should be noted that the siloxanes are dispersed in the lubricant in the form of small particles or globules with specialized equipment. These small particles can be seen through the use of a phase contrast microscope similar to that used in clinical laboratories.

Cavitation is a violent condition typically in the suction of a pump leading to wear caused by air bubbles or water or oil vapour bubbles.

Air can be present in four forms:

- Free air - such as a pocket of air trapped in part of a system.
- Dissolved air - hydraulic fluid contains between 6 & 12 percent by volume of dissolved air.
- Entrained air - air bubbles typically less than 1 mm in diameter dispersed in the fluid.
- Foam - air bubbles typically greater than 1 mm in diameter which congregate on the surface of the fluid.

Of these four forms, entrained air is the most problematic.

Pre-filling components and proper bleeding of the hydraulic system during start-up will largely eliminate free air.

Small amounts of foam are cosmetic and do not pose a problem. However, if large volumes of foam are present, sufficient to cause the reservoir to overflow for example, this can be a symptom of a more serious air contamination and/or fluid degradation problem.

Certain conditions can cause this dissolved air to come out of solution, resulting in entrained air.
When fluid temperature increases or static pressure decreases, air solubility is reduced and bubbles can form within the fluid. This release of dissolved air is known as gaseous cavitation.

Decrease in static pressure and subsequent release of dissolved air can occur at the pump inlet, as a result of:

Air entrainment can also occur through external ingestion. Like gaseous cavitation, this commonly occurs at the pump - as a result of:

Brendan Casey

Return pipes into hydraulic reservoirs should be larger than the intake pipes and should end below the surface of the oil in the reservoir. Locate the return as far away from the suction as possible to allow the oil as much residence time as possible. Better still, install a baffle between the suction and discharge. Cut the return pipe at an angle so that it directs the flow toward the tank wall.

1.9.1 What does 'synthetic' mean?

Synthetics - general

Petroleum-based mineral oils function very well as lubricants in 90 percent of industrial applications. However, they also have limitations depending on the type of base stock and additives used, the refining technology, and the operating conditions.

The formerly known manufacturer of Molykote lubricants has been Dow Corning, a joint venture between Dow Chemical and Corning Incorporated for over 73 years. In 2016 our parent company Dow Chemical took us over and last year we had a merger with Dupont.
Mathias Sottong

Silicone synthetic lubricants are used when resistance to oxidation, heat and/or water is important and the performance of other types of lubricants is unacceptable. Applications include high-temperature grease and the lubrication of oxygen compressors. Negatives for using silicone synthetics include high cost, poor boundary lubrication and poor additive solvency (they don't accept extreme-pressure and anti-wear additives).

Synthetic oils have better resistance to ageing and a longer service life, the time between oil changes could be three to five times that of mineral oils. Synthetic oils have improved thermal and oxidation resistance, improved viscosity/temperature characteristics, better low temperature properties and lower evaporation properties. In some instances, synthetic oils have less tendency to form residues.

1.9.2 Polyalphaolefins (PAO)

PAOs have inherently higher specific heats, so it will absorb more heat allowing the PAO-based lubes and the parts that they lubricate to run cooler.

One property that can improve a machine’s efficiency and lessen energy and fuel consumption is known as the traction coefficient. Consider that if you are able to decrease the amount of force required to move a load across a lubricant film, you can reduce the amount of fuel consumed and the number of emissions produced. The traction coefficient is simply the amount of force required to move a load divided by the load. The closer this ratio is to 1, the more force is required to move the load. As the ratio decreases, less force is needed to move the same load.

Mineral oils by nature have millions of combinations of molecular shapes and sizes in each drop. This inconsistency in molecular size results in a higher traction coefficient. Synthetic base oils are manmade compounds and have much more consistency in several key areas, including their fluid properties and molecular size. This allows a load to move more easily across the lubricant film, thus lessening energy consumption and emissions.

To envision how this works, imagine pushing a sheet of plywood across a series of balls. If the balls are different shapes and sizes (footballs, basketballs, baseballs, etc.), moving the piece of plywood becomes more cumbersome and awkward. Now if you took that same sheet of plywood and pushed it across a series of tennis balls, with each ball the same shape and size, it becomes much easier. This is why most synthetic oils come with claims of reducing energy consumption and can actually help to decrease emissions.

Sludge and varnish in hydraulic controls of turbines is not a problem with PAG turbine oils owing to their high solubility. However, some PAG turbine oils cause sudden oxidative degradation, resulting from a decrease in anti-oxidants due to poor thermal stability of those PAG base oils.

Neither mineral nor synthetic base oils can satisfy today’s lubricant performance requirements without using additives. Additives are chemical substances, in most part synthetic, which are used in lubricant formulations to adjust a broad of spectrum of properties by enhancing what is desired and suppressing what is unwanted. Many additives are multifunctional products that may exhibit synergistic or antagonistic behavior when mixed together. As a rule of thumb, additives do not add. This makes balancing and optimization of additive systems a challenging task.

1.12 Supplemental ('proprietary') additives

Blue exhaust smoke indicates an engine is headed for serious mechanical failure due to a high oil ingress into a combustion chamber. This means an engine is burning too much oil due to worn intake valve guides or poor piston ring control – collapsed or worn rings.
A useful rough guide to measuring oil consumption is the ratio of oil consumption to fuel consumption, because the harder an engine works (fuel consumption) the more oil it will use. A good estimate is 0,6% of total fuel consumption.

ZDDP reaction films formed on rubbing contacts produce enhanced friction in mixed lubrication conditions. The ZDDP reaction film appears to inhibit lubricant entrainment into the contact, thereby leading to a reduced EHD film thickness compared to ZDDP-free lubricants.

Turbocharged gasoline direct injection (TGDI) engines suffer from the presence of particulates in vehicle exhaust emissions, similar to a diesel engine. New oil specifications are needed to counter that.

Friction modifiers are most efficient under boundary conditions or where metal-to-metal contact occurs. Organic friction modifiers have long, soluble chains and a polar head. The polar head attaches to the metal surfaces. The soluble chains line up beside each other much like fibers in a carpet. The polar heads may be comprised of phosphoric or phosphonic acids, amines, amides or carboxylic acids. The soluble chains form dense mono layers or thick, reacted viscous layers. These layers shear easily and create a relatively slippery surface.

Corrosive wear occurs when a machine surface is damaged by chemical attack. The responsible corrosive chemical could be either vaporous or liquid, which might be found in a plant that mixes or handles strong acid or alkali materials. Often the damage to lubricated surfaces comes from acidic by-products generated by the deterioration of the lubricant.

Fresh engine oil (before it gets into the engine) normally has a cleanliness level in the range 16/xx to 18/xx. As soon as it gets into the engine, the cleanliness drops one-two levels because of mixing with the remaining old oil. An oil is "dirty" when cleanliness drops to 21/xx to 23/xx.
Prof. Dr Boris Zhmud

The lubricant in a crankcase engine is subjected to very complex conditions, with many different conditions in different parts of the engine, variable patterns of driving behavior, and, critically, the contamination of the lubricant by reactive combustion gases and particulates. This makes it very difficult to relate engine/lubricant performance to simple bench tests, and a key feature of engine oil development and testing is the use of engine tests to assess the behavior of the lubricant in the complex combination of conditions present in a firing engine.
Automotive Lubricants and Testing

API Service Category CK-4 describes oils for use in high-speed four-stroke diesel engines designed to meet 2017 model year on-highway and Tier 4 non-road exhaust emission standards as well as for previous model year diesel engines. These oils are formulated for use in all applications with diesel fuels ranging in sulphur content up to 500 ppm (0.05% by weight). However, the use of these oils with greater than 15 ppm (0.0015% by weight) sulphur fuel may impact exhaust after-treatment system durability and/or oil drain interval.
API CK-4 oils exceed the performance criteria of API CJ-4, CI-4 PLUS, CI-4, and CH-4 and can effectively lubricate engines calling for those API Service Categories - they are backward compatible.
API Service Category FA-4 describes certain XW-30 oils formulated for use in high-speed four-stroke diesel engines designed to meet 2017 model year on-highway and Tier 4 non-road exhaust emission standards with diesel fuel sulphur content up to 15 ppm (0.0015% by weight). Refer to individual engine manufacturer recommendations regarding suitability of API FA-4 oils.
API FA-4 oils are not interchangeable or backward compatible with API CK-4, CJ-4, CI-4 PLUS, CI-4, and CH-4 oils.
With the introduction of API CK-4 and API FA-4 diesel engine categories, Cummins developed two new standards, CES 20086 and CES 20087. Cummins has updated its CES 20086 list of API CK-4 registered oils, Cummins CES 20087 lists API FA-4 registered oils.

John Deere developed JD 303 in 1930 and replaced it 1974. Products making exclusive JD 303 claims can no longer be tested for compliance. JD 303 was replaced with J14-B, which was then replaced in 1978 with J20-A. John Deere has declared all of those specifications obsolete and has two current specs – JDM-J20-C and J20-D (which are backward compatible) – along with its genuine Hy-Gard fluid. Some lubricant marketers have continued marketing hydraulic tractor fluids labeled as meeting the 303 standard but critics say they do not meet the lubrication requirements of modern tractors and, in fact, can harm them.

At pressures above about 3000 psi (206 bar) there begins a significant increase in the viscosity of mineral oils. At 5000 psi (345 bar) the viscosity of a typical Group I base oil is approximately double its viscosity at atmospheric pressure. At higher pressures, the rate of viscosity increase accelerates and at very high pressures mineral oils cease to behave like liquids and tend to become waxy solids. Pressure viscosity coefficients are different for different types of oils, particularly for synthetic oils.

Metal sulfite, or Molybdenum disulfide (MoS2), is widely used as an additive in solid lubricants because of its low friction properties and robustness. However, at low loads or resistance, it shows excessive wear and higher friction.

A novel definition by Noria:
Film strength can be described as the lubricant’s ability to lessen the effects of friction and control wear by means other than the film thickness. As mentioned, the viscosity is the primary contributor to film thickness during hydrodynamic and elastohydrodynamic lubrication.
When the base oil viscosity is insufficient to overcome metal-to-metal surface contact, the base oil and additive chemistry work together to create a surface protection mechanism. During these boundary conditions, boundary lubrication is also influenced by the chemical and physical properties of the mechanical surfaces and any contributing environmental factors.
See the following article:

Overfilling a gearbox sump can be just as damaging as underfilling. Overfilling may cause air entrainment and foam, overheated oil, and leakage due to overflow. Over time, oxidation may also occur due to increased temperatures and exposure to air.

When receiving a new or reconditioned gearbox, open the drain plug and pump fresh oil through the system. This removes any contaminants that might not have been cleaned out during a rebuild or from a new machine. This will ensure your critical equipment has a better chance of reaching its life expectancy rather than coming to a grinding halt because of unforeseen contamination.

7. Greases (also 7.3, 7.5 and 7.7)

Grease life is not only determined by the operating conditions and bearing type. The grease type and grease quality are also very important. A good grease has a stable consistency, good shear stability, favourable bleeding and flow properties, and good boundary lubrication, including lubricity properties. The base oil viscosity should also be favourable for the speed and temperature.

The bleeding rate, which is the bleeding per unit of time, should ideally somehow match the starvation rate. In the beginning of bearing operation, the lubricant film will be relatively thick and no additional feed of base oil is required. A too high bleeding rate will exhaust the grease at an early stage, leading to short grease life. If the bleeding rate is too low, the contacts will starve rapidly, leading to early damage.

When using automatic grease lubricators that are set for several months, draw a line and record the date at the level of the lube during each weekly inspection. This allows you to instantly spot a plugged or faulty lubricator.

Large, abrasive particles in grease may be more damaging than the same particles in oil because once the grease is applied, no opportunity exists for the contaminant particles to be removed; whereas in oil, the particles may be quickly removed by filtering. The particles in a grease sample may be scrutinized by dissolving the grease with a suitable solvent and then preparing a ferrogram. A mixture of toluene and hexane is effective at dissolving many commonly available greases.

Applying a nice, thin layer of grease to sliding surfaces such as boom slides, crane outriggers or any sliding surface can be a problem. By using a regular paint roller of whatever size fits your application (2-inch, 4-inch, etc.), you have the ability to roll a nice, thin coat of grease on the area instead of all over yourself. Paint-roller pans work great and are available with snap-on covers to keep grease clean until you need to use it.
Al Allen, Sundt Construction

Grease guns and systems

(Beyond the scope of the book)

Before installing grease into a new grease gun, consider disassembling the gun and cleaning it thoroughly. I have found metal shavings numerous times in different brands of new grease guns. The metal shavings appear to be from the manufacturing process of the grease gun. (John Flynn, RJ Reynolds Tobacco Co.)

7.1 and 7.2 Grease thickeners, polymers and compatibility

Polyurea greases have excellent oxidation resistance because they don't contain metal soaps such as calcium, lithium, etc., which are pro-oxidants to varying degrees. Therefore, they are widely used in lubed-for-life bearings.

When converting from one grease to another, double check to make sure that your soap bases and oils are compatible. The short and simple way to do this is to have your supplier or an independent test lab perform a worked penetration test on a mixture of the greases. Mixing greases can change performance. More often, mixing leads to loss of consistency, but for some mixtures, hardening may occur. Mixing of greases can also result in lowering of dropping points and changes in oil bleed rate. Individual grease lubricants most often perform better than the grease mixtures.

Temporary shear thinning at a high shear rate happens in greases but the base oil viscosity may be permanently reduced. This happens under extreme conditions, such as in the case of high pressure, where the viscosity is very high. These conditions occur in the EHL contacts of rolling bearings. That's why viscosity modifiers (VI improvers) should not be used in bearing (and gear) oils.

Outer-ring rotation causes very severe conditions for the grease in the bearing. The grease on the shields or covers is subjected to centrifugal forces exceeding the yield stress, resulting in the grease flowing continuously into the bearing and causing churning, heat development and high temperatures. Moreover, grease on the bearing outer-ring shoulders or seals will show accelerated oil bleeding. In the case of outer-ring rotation, the base oil/grease is easily lost, and good sealing is therefore a prerequisite.

Roller bearings require a softer grease than ball bearings (on a horizontal shaft). Angular contact ball bearings pump grease through the bearing from the small inner ring diameter side ("low side") to the larger inner ring diameter side ("high side"). In order to prevent this, ideally a stiff grease is preferred on the "low side" and a softer grease on the "high side." Vertical shaft applications require a stiffer grease to prevent grease falling into the bearing.

At very low temperatures, the tendency of grease to bleed decreases and the hardness (consistency) of the grease increases. This may ultimately lead to an insufficient supply of lubricant to the contact surfaces of the rolling elements and raceways so the normal lubricating ability of the base oil in the grease can be diminished. It will then be the grease in its totality that will lubricate. This will result in a high torque, which may cause slippage of the rolling elements and therefore wear. This point is called the low temperature limit (LTL).

When hand-packing roller bearings, wear disposable food-grade gloves. This has a two-fold effect. First, it helps keep your hands free from grease, but it also helps keep the bearing free from contaminants. Particles and chemicals on hands can lead to premature bearing failure. (Jason Throop, Sara Lee Corp.)

Advantages of oil mist systems:
In bearing applications where high contamination levels are a concern, consider converting grease lubrication systems to oil mist lubrication. Oil mist systems are slightly pressurized, helping to exclude contaminants. Use a pure mist system for rolling-element bearings and purge mist for gearboxes and journal bearings.
Noria's Machinery Lubrication I training

7.6 Grease-filled gearboxes

Grease-lubricated equipment should not be kept idle for long periods. The base oil in the grease could separate out and get drained from the thickener, which does not have any lubrication properties. Stop and think about all of your equipment to evaluate the potential risks of grease separation.

When a properly packed bearing starts up, there will be an initial rise in the temperature while the grease disperses throughout the bearing and the housing before falling off to a steady operating temperature. If the temperature does not drop, then there is too much grease in the bearing or there is a problem with the bearing fit.

The top 10 causes of bearing failures:

1. Lack of lubrication training
2. Lack of lubrication-application engineering
3. Poor housekeeping (lack of order and cleanliness)
4. Over-lubrication of bearings
5. Under-lubrication of bearings
6. Use of dirty or contaminated new lubricants
7. Infrequent oil/filter changes
8. Bearing lubricant contaminated with an incompatible lubricant
9. Bearing lubricated with the incorrect lubricant
10. Bearing mounted out of square or misaligned when set up

Note that nine out of 10 items on this list are due directly or indirectly to ineffective lubrication practices.

The Shell Clavus 68 was a naphthenic oil recommended for all types of refrigeration systems such as ammonia, and CFC and HCFC refrigerants e.g. R-11, R-22, R-500, R-502, R-22, and R-123. The Clavus oils were not recommended for use with HFC refrigerants such as R-134a.

Shell Refrigeration Oil S4 FR-F 68 is a synthetic polyol ester base fluid that is recommended for use with R-134a and other HFC refrigerants and blends. According to the literature, it is not recommended for use with other refrigerants such as R-22.

Shell Refrigeration Oil S4 FR-V 68 is a synthetic refrigeration lubricant based upon alkylated benzenes. It offers a universal solution to the lubrication requirements of most refrigeration compressors and is compatible with all commonly used refrigerants such as R-22 with the exception of HFCs such as R-134a. However, S4 FR-V 68 base stock is not compatible with Clavus 68 and if you are switching you need to thoroughly flush the system including lines and pump to prevent compatibility issues.

It is possible, but not desirable, that a big machine, like a Komatsu PC1250-7 hydraulic excavator, of this size, with its large number of conductors and connections could lose 5% or more of tank oil volume per annum through slow leaks; weeps and drips.
Brendan Casey

Baffles are used to prevent fluid just returned to the tank from passing directly back to the pump inlet. For a number of reasons, a longer transit path is considered beneficial; it encourages better heat conduction from the fluid, better contamination and air separation, and better mixing with the bulk fluid. This is usually accomplished by separating the inlet and outline by as long of a flow path as feasible.

Suction line leaks can cause air entrainment and problems such as excessive aeration, air lock, pump cavitation, poor lubrication and premature oil degradation. While a pinhole-sized suction line leak can be hard to find, using a small amount of shaving foam sprayed over the suspected leak area can indicate the source of the problem, as the foam is drawn into the line. This method should not be used for large leaks, and care should be taken not to use too much soap, since this can cause contamination of the lube, resulting in foaming and aeration problems and poor demulsibility.

Factory Mutual, FM Global, is a US-based mutual insurance company which assists businesses worldwide. The company carries out its own scientific research, approves fire protection equipment (FM Approvals) and publishes its own installation regulations (FM Data Sheets - FMDS). FM Global assesses the risks of its policy holders, appoints a project engineer to produce protection system recommendations and, upon completion of the work, the project engineer is brought in to verify that the protection provided complies with his recommendations. FM Data Sheets are recognised standards for fire protection in industry. They are available to consult free of charge and other insurers may use them as their standard.

Given a high enough temperature, all hydraulic fluids can be ignited when coming into contact with an ignition source. The real test of fire resistance is whether a fluid is capable of self-extinguishing. The ability to self-extinguish can make the difference between a momentary flash that causes no harm and a conflagration, which results in injury to personnel and/or loss of equipment. Only phosphate esters offer such fire-resistant characteristics.

Trixylenyl phosphate fluids are used in large steam turbines of nuclear power plants where temperatures reach high enough to ignite mineral oils. These synthetic fluids are extremely difficult to ignite and inherently self-extinguishing. Besides their high oxidative and thermal stability, they can contain water and have good hydrolytic stability.

Avoid the use of galvanized steel storage and dispensing containers. The zinc in the galvanizing can act as a catalyst to promote lubricant oxidation and premature depletion of critical additives. There are many other types of more chemically stable platings for metal containers. Stainless steel or plastics are also suitable alternatives.

The oil in a transformer serves as an insulating medium which is used for cooling, protecting the paper and for analysis. Regular oil analysis is considered one of the most critical activities that will assist in monitoring the condition of the transformer and facilitate predictive servicing. The oil analysis regime should include dielectric strength, water content (Karl Fischer), acidity, interfacial tension and dissolved gas analysis (DGA) that provides a clear indication of internal failure conditions.
The oil should be analysed to determine if polychlorinated biphenyls (PCBs) are present.
Furanic analysis should also be done as this will determine the cellulous breakdown products in the oil and give an indication of the life expectancy of the insulation in the transformer.
High moisture will result in dielectric breakdown.

Lead enhances metal machinability. Traces of lead are added to steel, aluminium and copper alloys for rapid, accurate and efficient machining with currently available tools and metalworking fluids. The lead reduces friction between machine tools and parts, allowing faster production of parts and lower energy consumption.

Oil mist is effective in protecting stored machines. The Caltex Thailand Refinery added a new dimension to the capabilities of oil mist lubrication by using it to preserve rotating machines while they were sitting in storage yards. The machine manufacturers connected tubing from the oil mist connections on the machines to connectors on the sides of the shipping crates. A temporary system was connected to the crates upon their arrival to the yard. Typically, upon startup, there are numerous bearing failures. In this case, there were virtually none.
Douglas Branham, Lubrication Systems Co.

Lubricant monitoring, sampling and analysis

Monitoring equipment without special instruments and without laboratory samples

Oil analysis is not simply about a periodic sample pulled from a machine and sent to a laboratory. A lot of organisations today are empowering their maintenance staff and operators to do a certain amount of quick, on-site inspections and field tests. The concept of a frequent inspection, what is called a daily one-minute inspection, can far exceed the benefits of monthly or bimonthly oil sampling where very sophisticated laboratory testing is done.

Many equipment inspections are visual, and checking oil levels is the most common visual monitoring activity. Numerous potential machine failures are prevented by an attentive individual who notices a low oil level. Other valuable functions can also be performed as part of the visual inspection. Lubricant issues such as oil contaminated with water or other materials, badly degraded or oxidized oil, and excessive foaming, as well as other machine conditions including excessive vibration, loose belts, loose drive chains and loose or missing fasteners are all examples of what should be routinely documented and scheduled procedures.

In machinery condition monitoring, a decision on the condition of a machine is dependent on the nature of its signals. For example, if the machine produces excessive noise and vibration, one gets a clue that something is not normal with the machine. These signals are usually time varying and need to be understood because they carry the information from the machine to the decision system, which can be a developed software or a person.

Temperature is a very important parameter to be monitored, in particular for bearings and shaft couplings. Many instruments are widely used for temperature measurements. At high temperatures, when mounting or access to machines is a problem, non-contact instruments like pyrometers and thermal imaging cameras are appropriate.

While pulling a sample from a reservoir, an exceptional amount of air was found in the hydraulic fluid. The suction-side components were sprayed with mineral oil to locate where air was being ingested. The pump became quieter after the input shaft seal was sprayed. The sprayed oil was seen being drawn into the pump. A check of the pump revealed a worn bearing and shaft seal, which were attributed to oil contamination. The pump was replaced, and the source of contamination entry was located. The bottom line is to listen when your oil talks to you.
Mike Deal, Alcan Aluminum

Chemists might refer to the blotter spot test as paper chromatography. It dates back to the early days of the lubrication industry in the mid-1800s and is still used today. It has been utilized for a variety of different reasons, including to assess the condition and quality of oil.

In time-critical situations where real-time infrared thermography is impractical and thermocouple/recording equipment cannot be installed, consider temperature-sensitive tapes. These tapes are manufactured in a variety of sensing ranges and will clearly record the peak temperature that a machine area reached since the tape was first applied. A quick visual check is all it takes to read the "paper thermometer.
Mark Smith, Analysts Inc.

Oil and grease sampling

SUMMARY: Effective oil sampling

The sampling technique that gives the most representative sample is one in which the sample is taken from a pipe carrying oil scavenged from the wearing parts and before filtering. Clearly, it is necessary for the machine to be operational to do this. Care must be taken that the sample is representative of the complete system, i.e., that the scavenged oil has passed through all the wearing parts.

To achieve the most representative and 'trendable' information from oil sampling, follow these basic tips:

1. Samples should be collected when machines are running at normal operating temperatures, loads, pressures and speeds. This will ensure that insoluble and semi-soluble (dirt, water, and other debris) material is suspended evenly throughout the system.

2. Sample upstream of filters and downstream of machine components such as bearings and gears to obtain the best data. Sampling downstream from the filters should be performed if you wish to determine the effectiveness of your filtration system.

3. Document oil sampling procedures for each system - tools needed, line flushing requirements, sampling locations, sampling methods, and safety requirements are among some of the items to include in the written procedures. This ensures that each sample is taken in the same manner and from the same point. Procedures that are documented also help new employees quickly learn the process.

4. Properly flush sampling valves, devices, and hardware thoroughly prior to taking oil samples. To avoid cross-contamination, use a new sampling tube for each sample taken.

5. Make sure that oil samples are taken at the proper frequency and that the frequency is sufficient to identify problems. Sampling frequencies should be set specifically for a particular machine. Every machine is unique in its intended performance, condition, locality, operating environment, and maintenance schedule.

6. Forward samples immediately to the lab after sampling. Ideally, oil should be analysed within 48 hours of being sampled.
Trico Corporation

When possible, don't take oil samples from cold systems. Samples that are consistently collected from cold systems will have altered concentrations of wear metals, contaminants and other insoluble suspensions. When at rest, anything heavier than the oil will begin to settle. It takes only two minutes for a 20-micron particle of Babbitt bearing metal to settle 1/2 inch in an ISO 22 bearing oil. If unavoidable, cold systems should be labelled as such.

With the proliferation of digital cameras, why not take a photograph of the oil sample (requires the use of a transparent sample bottle) and store the image in a trending software for comparative purposes. Record a new oil sample and use this as a baseline. Set the bottle against a white background such as a sheet of paper to maintain a consistent color comparison. You can also use the camera in other ways such as to record images of the machine and sampling point as a means of identifying it in the software or to record abnormalities.

Sampling frequencies

The appropriate sampling frequency is determined by the nature of the machine, its use and how important early warning is to the user. Experience has shown that in many failures abnormal wear particles were present in the lubricant, indicating that the machine was defective from the start. The reasons for this are easy to see. Many failures are the result of improper assembly, a defective part or poor design. Such difficulties result in abnormal wear debris from the beginning.

A major mobile equipment manufacturer estimated that an average of 53 percent of all engine failures are a direct result of problems with the cooling system. Periodic coolant analysis, including glycol content, pH, conductivity, inhibitor analysis, visual inspection and resistance to corrosion, may be as valuable as routine oil analysis in preventing failure due to the cooling system.

While oil analysis can't fix a failed machine, it can provide pre-failure alerts, both cautionary and critical. If a root cause is detected, such as the wrong oil, dirty oil or wet oil, these conditions can then be remedied quickly.

According to the Electric Power Research Institute (EPRI), online monitoring is the implementation of applications for monitoring, maintaining, and optimizing assets from a centralized location. Such monitoring becomes necessary in today's fast-evolving global economy for companies that rely on assets as they face increasing reliability concerns. Unexpected downtime and maintenance can lead to significant cost and safety repercussions that can easily affect a company's bottom line.

Oil analysis reports also frequently lack important test information relating to the machine application and the type of oil, which is essential for proper interpretation. Other common challenges include:
* The same test package is used for different types of machines.
* The individual reading the oil analysis report lacks the appropriate knowledge/understanding.
* The laboratory analyst has no knowledge of the basics of machinery lubrication and tribology.
* The oil analysis report is received several months after oil sampling.
* The lab does not follow strict procedures as per ASTM/ISO standards.
* There is no quality assurance for meeting the required standards.
* The report contains insufficient information to make any decisions.
* No interpretation or recommendation by the oil analysis lab is included in the results.
* Cross-contamination between various oil samples leads to inaccurate results.
Mohammad Naseer Uddin

According to Caterpillar, catching a problem before failure occurs results in repair costs that are 5 to 25 percent of the engine's value. Catching a problem after failure occurs leads to repairs that are more than 65 percent of the engine's value.

Today, portable analysers are able to measure many relevant oil parameters at the site with no need to send samples to a laboratory. They can determine oxidation, viscosity, TBN, TAN, water contamination, additive depletion and more.

Oil analysis reports frequently lack important test information relating to the machine application and the type of oil, which is essential for proper interpretation. Other common challenges include:
* The same test package is used for different types of machines.
* There is no reason to perform oil analysis if the data obtained is not properly understood. With so much information packed into a few pages, reading lab reports can be overwhelming to the untrained eye. Unfortunately, a majority of plant personnel who receive these reports do not understand the basics of how to interpret them.
* The laboratory analyst has no knowledge of the basics of machinery lubrication and tribology.
* The oil analysis report is received several months after oil sampling.
* The lab does not follow strict procedures as per ASTM/ISO standards.
* There is no quality assurance for meeting the required standards.
* The report contains insufficient information to make any decisions.
* No interpretation or recommendation by the oil analysis lab is included in the results.
* Cross-contamination between various oil samples leads to meaningless results.

When installing fine-filtration (3 to 10 micron) reservoir breathers, make sure the breather has an internal differential pressure gauge to alert you when the filter is dirty. If your breathers do not have this built in, add pressure and vacuum gauges to the reservoir head space. Then add inspection of these gauges to your pre-PM checks while the machine is in normal operation.

Translucent new oil is visually assumed to be clean but it often contains more contamination than the existing oil being replaced.

Equipment that is run in an extremely dirty environment, such as in a forge or foundry, needs extra care to avoid contamination. Always try to keep equipment sealed and avoid unnecessary opening of the reservoirs. Install quick disconnects in your tanks and on your fill vessels for filling or topping up hydraulic tanks. All equipment should have mainstream sampling taps installed for uptime or running sampling. This will result in a true indication of the oil condition, avoiding any bottom sampling.
James Ott, Patriot Forge Co.

There are generally only two conditions that necessitate changing the oil in a hydraulic system:
1. Base oil degradation
2. Additive depletion

Contaminants of the hydraulic fluid such as hard and soft particles and water can be removed from the oil and therefore don't mandate an oil change.

Techniques for flushing hydraulic systems vary in cost and complexity. Before I discuss some of these methods, let's first distinguish between flushing the fluid and flushing the system.

The objective of flushing the OIL is to eliminate contaminants such as particles and water.

This is usually accomplished using a filter cart or by diverting system flow through an external fluid-conditioning rig.

The objective of flushing the SYSTEM is to eliminate sludge, varnish, debris and contaminated or degraded fluid from conductor walls and other internal surfaces, and system dead spots.

Common methods for flushing hydraulic systems include:

The technique or combination of techniques employed will depend on the type of system and its size, your reliability objectives for the equipment and the reason for the flush.

Double oil and filter change
This technique involves an initial oil drain and filter change, which expells a large percentage of contaminants and degraded fluid. The system is then filled to the minimum level required and the fluid circulated until operating temperature is reached and the fluid has been turned over at least five times.

The oil is drained and the filters changed a second time. An appropriate oil analysis test should be performed to determine the success of the flush.

To maximize the effectiveness of this technique, the system should be drained as thoroughly as possible and the reservoir mechanically cleaned.

Mechanical cleaning
Although not technically a flushing technique, the selective use of mechanical cleaning may be incorporated in the flushing strategy.

This can involve the use of a pneumatic projectile gun to clean pipes, tubes and hoses, and disassembly of the reservoir and other components for cleaning using brushes and solvents.

Mechanical cleaning is labour intensive and therefore costly. It carries with it reliability risks associated with opening the hydraulic system and intervention by 'human agents'.

Power flushing
Power flushing involves the use of a purpose-built rig to circulate a low viscosity fluid at high velocities to create turbulent flow conditions (Reynolds number > 2000).

The flushing rig is typically equipped with a pump that has a flow rate several times that of system's normal flow, directional valves, accumulators, fluid heater and chiller and of course, a bank of filters.

The directional valves enable the flushing direction to be changed, the accumulators enable pulsating flow conditions and the heater and chiller enable the fluid temperature to be increased or decreased, all of which can assist in the dislodgment of contaminants.

Analysis of the flushing fluid is performed regularly during the flushing operation to determine the point at which the system has been satisfactorily cleaned.

What about components?
The question of how to deal with system components arises when contemplating a hydraulic system flush. Plumbing should be flushed first in isolation from pumps, valves and actuators. Once the conductors have been flushed clean, valves and actuators can be gradually included in the flushing circuit.

The decision to disassemble and mechanically clean components will depend on the type of equipment, your reliability objectives and the reason for the flush.

With the exception of new or overhauled equipment, the need to flush a hydraulic system generally represents a failure of maintenance.

If you follow an effective proactive maintenance program like the one I outline in 'Insider Secrets to Hydraulics', it's likely you'll never need to flush!
Brendan Casey

Filtration, filters

Be sure to monitor your filter change interval. Premature plugging is usually a sign of a problem that merits further investigation. This may be caused by airborne dust from nearby construction or a prolonged dry spell raising atmospheric dust levels. Whatever the source of dirt, the root cause should be investigated, and the seals or breathers may need to be serviced or upgraded. In certain cases, the problem may be associated with a change in the performance of the filter from your supplier. Extremely long filter life is as much of a concern as too short of a life.

Have you seen a spike in particle counts for a stable circulating oil system where no oil has been added or lost? Check to see if the oil filter was changed just prior to the sample date. It's not uncommon for a spike in particle counts to occur after changing filters due to the system "disturbance." Therefore, don't be too zealous in changing filter elements purely on a calendar basis. Take advantage of their operating life and only change them when they have reached load capacity or been in the system for the recommended service life.

Maintenance tip: Equipment optimisation through modification

More than 75% of all problems in fluid systems can be traced back to contaminated oil. Therefore, proper lubrication goes beyond choosing the correct lubricant; it includes keeping the lubricant free of contaminants and monitoring oil cleanliness is the most important factor in preventing system failures.
You might have to modify the equipment so it remains sealed during all phases of normal operation—including routine maintenance, such as level checks and oil changes. This can be achieved by retrofitting the drain and fill/breather ports with modification kits that permit multiple access points to the equipment without opening the sump to the environment. Modifications should be designed in a way to help you:
- Top up oil
- Check oil level
- Take oil samples
- Drain/fill oil
- Kidney loop oil filtering

Advice

When replacing top-suspended spin-on or threaded canister-type filters, fill them with fresh oil before installation. This will reduce the amount of time that the engine or machinery undergoes dry start-up by having that extra available amount of oil available. In some cases, it could also prevent filter damage when a gush of high-pressure fluid hits a dry element.

The limiting factor is inlet vacuum at the pump which I limit to less than 5 PSI via a pressure relief valve at the pump outlet which relieves back to the intake side of the inlet filter. That routing was chosen to provide rough filtration and more heat exchange surface for the oil being recirculated within the pump.

With cold hydraulic oil this gets me a throughput of around 1 GPM which I run for several hours to get several full passes. All very modest, but a real money saver. The alternative - annual oil changes - would cost around $450 at today's $15/gallon prices. The total cost of my self-made cart was less than that so it paid for itself in the first year. I suppose I should still change the oil every three years or so to maintain the additives and all. Even at that rate the cart will have reduced my oil cost to one third of what it would have been. Rather satisfactory."

Brendan Casey comments: Is this filter cart design technically perfect? Probably not. Is it effective at cleaning and drying the oil? Almost certainly. Sure, this member needs to get a bit more sophisticated and do regular oil analysis - to know for sure when the oil's additives and/or oxidative life have been used up.

Advice

High Velocity Oil Flushing is an essential process to ensure optimal reliability of critical components within hydraulic systems and the lube oil systems of rotating equipment.

Water contamination

Noria: The presence of water in most lubricants (synthetic or mineral) can cause the progression of oxidation to increase tenfold, resulting in premature aging of the oil, especially in the presence of catalytic metals such as copper, lead and tin. In addition, certain types of synthetic oils like phosphate esters and dibasic esters are known to react with water, which leads to the destruction of the base stock and the formation of acids.
It is not just the base oil that can be affected by moisture contamination. Certain additives such as sulfurous anti-wear (AW) and extreme-pressure (EP) additives as well as phenolic antioxidants are readily hydrolyzed by water, causing both additive mortality and the formation of acidic by-products. These acidic by-products can produce corrosive wear, particularly in components containing soft metals like Babbitt, which is used with journal bearings, as well as bronze and brass components. Other additives, including demulsifying agents, dispersants, detergents and rust inhibitors, can be washed away by excessive moisture. This results in sludge and sediment build-up, filter plugging and poor oil/water demulsibility.

In turbine oils, moisture content could reach 180 ppm before the oil turns cloudy. So the easiest way to check for water is visual, done at room temperature. At 250 ppm, the lubricant is still translucent but hazy. At 500 ppm, it is hazy and opaque. At that level, by decreasing water concentration, lubricant's service life extends almost twice for every 120 ppm water eliminated. There is also the crackle test: if no crackling takes place after placing a drop of oil for a few seconds on a small metal pan at 135 °C, no free or emulsified water is present. If some 0,5 mm bubbles are produced aprox. 500-1000 ppm water is present. For moisture content of more than 2000 ppm, bubbles grow to 4 mm. This method does not measure chemically dissolved water. Other methods would be calcium hydride test and capacitance change of the sample or FTIR or Karl Fischer.
Denisa Ivana

It's always wise to control water contamination at the lowest levels that can reasonably be achieved, but certainly below the oil's saturation point at operating temperature.

Polymeric filters - These look like conventional particulate filters, however the media is impregnated with a super-absorbent polymer.

Water causes the polymer to swell, which traps the water within the media. Polymeric filters are best suited for removing small volumes of water and/or maintaining water contamination within pre-determined limits.

Vacuum distillation - This technique employs a combination of heat and vacuum. At 25 inches of mercury, water boils at 56 °C. This enables water to be removed at a temperature that does not damage the oil or its additives.

Head space dehumidification - This method involves circulating and drying the air from the reservoir head space. Water in the oil migrates to the dry air in the head space and is eventually removed by the dehumidifier.

Vacuum distillation and head space dehumidification also remove dissolved water.

Like all other forms of contamination, preventing water ingress is ten times cheaper than removing it from the oil.
Brendan Casey

SKF recommends a conservative 200 ppm limit of water content. This can be achieved with desiccant breathers and proper water removal techniques (vacuum separation, centrifugal separation). Most circulating systems have tanks to allow some standing time to promote separation.

Some greases and oils can carry as much as six percent water when mobile. Water separates readily at a standstill and displaces oil on metal surfaces - attacking metal surfaces directly. Avoid standstills with water in the system if possible.

A good way to get an estimate of the concentration of water in oil is to use the calcium hydride method. There are different suppliers and variations on how to do this. The basic concept is that you put some oil and kerosene into a vessel. The instrument that you buy will have this vessel as a part of it. A calcium hydride capsule is placed in with the kerosene and oil. The vessel is then sealed and agitated.

In humid environments, condensate can form in rolling-element bearings and cause corrosion, leading to a reduction in bearing life. The condensed moisture's effect can be reduced by carefully choosing the grease lubricant. Greases thickened with sodium soap will absorb (emulsify) large quantities of water but may soften it to such an extent that the grease flows out of the bearing. Lithium soap greases do not emulsify water but with suitable additives can provide good protection against corrosion.

Although grease can absorb large quantities of water, separation occurs due to pressure and shear, leading to free water. This does not have an impact on the film thickness under fully flooded EHL conditions. However, water does have an effect on the film thickness under starved conditions where the differences are related to the change in oil bleed. In the presence of water, an increase in oil bleed was found for lithium, lithium complex and polyurea grease. These greases showed a reduction in the levels of starvation and, therefore, thicker films. Water contamination led to lower oil bleed for calcium sulphonate complex greases, which led to an increase in starvation, and therefore, thinner films compared to their uncontaminated counterparts.

1. Educate maintenance staff to avoid direct jetting of water at ingression points such as shaft seals and breathers, etc.
2. If water spray is inevitable, use passive shields and deflectors to avoid direct water spray on shafts, dipsticks, fill-caps, breathers, etc.
3. Use high-performance seals that suffer less wear and offer better protection against contaminants.
4. Regularly inspect and maintain gaskets on fill-caps, hatches, etc.
5. Replace dipsticks with level indicators.
6. Keep hatches closed tight.
7. Replace a basic vent breather with a desiccant breather, which dehydrates incoming air, or an expansion chamber, which allows the system to breathe without ingesting external air.
Noria

Combining effective failure analysis with a good predictive maintenance program usually results in huge benefits. Depending on the type of facility, it can not only reduce maintenance costs by 20-30 percent but also increase production by similar values. However, it does require a cultural change.

The cost of a reactive maintenance program can be up to 10 times that of a proactive approach.

Data proliferation: There will be a mountain of data types with the advent of holistic CM and the varied techniques and disciplines utilized. Powerful intelligent agents (IA) will be needed. That means that manual evaluation would be almost impossible and add unnecessary risk of missing subtle patterns.

Reliability Centred Maintenance (RCM) was originally called On-condition Maintenance, a term coined by the commercial airline industry. Three surprising discoveries were made:
(1) Scheduled overhaul has little effect on the overall reliability of a complex item unless the item has a dominant failure mode.
(2) There are many items for which there is not an effective form of scheduled maintenance.
(3) Preventive maintenance actually increased the rate of failure in some cases. Scheduled maintenance tends to increase breakdowns, and this can only be because it is doing harm by disturbing a relatively satisfactory state of affairs.

The most influential mentor of my career died on January 15, 2004. Thirteen years later, John Moubray’s wisdom continues to serve me. If you have anything to do with Reliability Centered Maintenance (RCM), then you know who John Moubray was. No matter what your perspective is on RCM2, there’s no denying that John was a giant in the RCM world; he was a fierce proponent of the RCM philosophy designed by the original architects, Nowlan and Heap. He trained his network members to be responsible custodians. John said it best when he affirmed: we are here to promulgate the principles we believe to be best practice and in so doing make the world a safer place for all who live in it. In 1997, by luck (or Providence), I stumbled upon Aladon LLC and the RCM2 process, and thus began my journey into RCM. John Moubray became my mentor. This presentation summarizes the most important RCM lessons John delivered about the process he described as “majestic.” However, a keen entrepreneur, John’s wit and wisdom extended beyond RCM. This presentation also features his insights on business and life that are just as relevant (if not more relevant) today as they were nearly twenty years ago. Ever-grateful for the treasure of John Moubray’s philosophy, the presentation ends with the most valuable advice he ever gave me – advice that applies to everyone (and has nothing to do with RCM!). Nearly two decades later, I finally get it!
Nancy Regan

Reliability resolutions for improving operations and maintenance:

1. We will provide leadership and communication about organisational changes.
2. We will train in best practices and provide on demand refreshers.
3. We will expand our maintenance planning into day-to-day tasks.
4. We will keep our schedule updated 4 weeks in advance.
5. We will solve problems and eliminate reoccurring failures.
6. We will capture both useful data and site knowledge.
7. We will let the equipment talk to us via the condition based tools.

Maintenance/Industry 4.0, Internet of things (IoT), CMMS

With the implementation of computerized maintenance management systems (CMMS), the manufacturing industry became incredibly more efficient. A CMMS tracks system maintenance, inspections and breakdowns, making system disruptions smaller and even obsolete. Instead of manually tracking problems or changes on a piece of paper, a CMMS handles all of this remotely, increasing productivity. The benefits include fewer repairs, lower maintenance costs, a streamlined workforce, and historical data and trend reports.

CMMS technology also connects devices remotely, allowing them to "talk" to each other. Often referred to as the Internet of Things (IoT), it connects factories to the Internet, enabling automation and remote monitoring. Rather than a manual check, the IoT allows systems to be connected to each other and essentially monitor each other's process.

With this connection, plants can easily collect and aggregate big data, or a mass of information concerning their systems. This information can be measured and analysed to increase productivity and efficiency. The IoT helps manufacturers work better by getting products to consumers faster.

Last word

The machine and the lubricant can telegraph hints and signals to us in a variety of ways, but only if we are both tuned in and literate to their message. Tuned in means being vigilant and ubiquitous, like a detective, always looking for clues even when camouflaged from view. Literate means not only recognising the presence of the clue but also being wise to the meaning of its message and the corrective response.

Condition-based maintenance is based on identifying measurable criteria that allows the time to plan for early intervention on failures, thus helping to reduce catastrophic and secondary damage. The earlier you are able to detect the failure, the more time you will have to prepare the spares, ensure labour resources and communicate the need to everyone.

A best practice tends to spread throughout an industry after a success has been demonstrated. However, demonstrated best practices can often be slow to implement, even within an organisation. The three main barriers to adoption of a best practice are a lack of knowledge about current best practices, a lack of motivation to make changes for their adoption, and a lack of knowledge and skills required to do so.

Light reading

The term tribology was mentioned for the first time in 1966 in the Jost Report, a study commissioned by the British government to investigate damage from wear. The committee headed by Peter Jost (1921-2016), estimated that application of basic principles of tribology could save the UK economy approx. ₤515 million per annum (1966).

Dictator of Equatorial Guinea, Francisco Macias, banned the use of lubricants in the Malabo city power plant, claiming that he has magical powers. The plant exploded.

Now seriously

Some time ago the International Fluid Power Society produced a webinar on the prevention and management of fluid injection injuries. It cited a study by Snarski and Birkhahn, two emergency department doctors at the New York Methodist Hospital, which contained some very sobering statistics:
* Fluid injection injuries are relatively rare with around 600 incidences in North America per year. That's the good news. The bad news is it means your average emergency department doctor may not recognize the seriousness of the situation.
* High-pressure grease guns/systems account for 57% of injection injuries. Paint, hydraulic oil and similar fluids account for 18%. And diesel fuel injectors 14%.
* The overall incidence of medical amputation resulting from such injuries is 48%. But if the injection pressure is greater than 7000 PSI, the amputation rate approaches 100%.
* The average elapsed time between occurrence of injury and seeking medical attention is 9 hours. This is attributed to the apparent benign nature of initial injection, combined with a lack of awareness of the seriousness of this type of injury.
* Disturbingly, where 10 hours or more elapses between occurrence of injury and medical intervention, the amputation rate approaches 100%.
Bottom line: fluid injection injuries are medical emergencies which typically require surgical intervention to release the injected fluid and limit the tissue damage it causes. This is something everyone who works on or near hydraulic machines needs to be aware of.
Brendan Casey